Polymer compositions are being increasingly used in a wide range of areas that have traditionally employed the use of other materials such as metals. Polymers possess a number of desirable physical properties, are light weight, and inexpensive. In addition, many polymer materials may be formed into a number of various shapes and forms and exhibit significant flexibility in the forms that they assume, and may be used as coatings, dispersions, extrusion and molding resins, pastes, powders, and the like.
The various applications for which it would be desirable to use polymer compositions require materials with electrical conductivity. However, a significant number of polymeric materials fail to be intrinsically electrically or thermally conductive enough for many of these applications.
Graphene is a substance composed of pure carbon in which atoms are positioned in a hexagonal pattern in a densely packed one-atom thick sheet. This structure is the basis for understanding the properties of many carbon-based materials, including graphite, large fullerenes, nano-tubes, and the like (e.g., carbon nano-tubes are generally thought of as graphene sheets rolled up into nanometer-sized cylinders). Graphene is a single planar sheet of sp2 bonded carbon atoms. Graphene is not an allotrope of carbon because the sheet is of finite size and other elements can be attached at the edge in non-vanishing stoichiometric ratios.
When used to reinforce polymers, graphene in any form increases polymer toughness by inhibiting crack propagation. Graphene is also added to polymers and other compositions to provide electrical and thermal conductivity. The thermal conductivity of graphene makes it an ideal additive for thermal management (e.g., planar heat dissipation) for electronic devices and lasers. Some commercial applications of carbon fiber-reinforced polymer matrix composites (CF-PMCs) include aircraft and aerospace systems, automotive, electronics, government defense/security, pressure vessels, and reactor chambers, among others.
Progress in the development of low cost methods to effectively produce graphene-reinforced polymer matrix composites (G-PMCs) remains very slow. Currently, some of the challenges that exist affecting the development of G-PMCs viable for use in real world applications are that the materials used are expensive and the presently used chemical or mechanical manipulations have not been practical for large-scale commercial production. It would thus be desirable for a low cost method to produce a G-PMC suitable for large-scale commercial production that offers many property advantages, including increased specific stiffness and strength, enhanced electrical/thermal conductivity, and retention of optical transparency.